/* global ajaxurl, tinymce, wpLinkL10n, setUserSetting, wpActiveEditor */
var wpLink;

( function( $ ) {
    var inputs = {}, rivers = {}, editor, searchTimer, River, Query;

    wpLink = {
        timeToTriggerRiver: 150,
    minRiverAJAXDuration: 200,
    riverBottomThreshold: 5,
    keySensitivity: 100,
    lastSearch: '',
    textarea: '',

    init: function() {
        inputs.wrap = $('#wp-link-wrap');
        inputs.dialog = $( '#wp-link' );
        inputs.backdrop = $( '#wp-link-backdrop' );
        inputs.submit = $( '#wp-link-submit' );
        inputs.close = $( '#wp-link-close' );
        // URL
        inputs.url = $( '#url-field' );
        inputs.nonce = $( '#_ajax_linking_nonce' );
        // Secondary options
        inputs.urlType = $( '#url-type-field' );
        inputs.title = $( '#link-title-field' );
        // Advanced Options
        inputs.openInNewTab = $( '#link-target-checkbox' );
        inputs.search = $( '#search-field' );
        // Build Rivers
        rivers.search = new River( $( '#search-results' ) );
        rivers.recent = new River( $( '#most-recent-results' ) );
        rivers.elements = inputs.dialog.find( '.query-results' );

        // Bind event handlers
        inputs.dialog.keydown( wpLink.keydown );
        inputs.dialog.keyup( wpLink.keyup );
        inputs.submit.click( function( event ) {
            event.preventDefault();
            wpLink.update();
        });
        inputs.close.add( inputs.backdrop ).add( '#wp-link-cancel a' ).click( function( event ) {
            event.preventDefault();
            wpLink.close();
        });

        inputs.urlType.change(function() {
            if ($(this).val().match(/^\[[a-zA-Z0-9]+\]$/)) {
                $('#link-href-field, #search-panel').hide();
                $('#wp-link-wrap').removeClass('search-panel-visible');
            } else {
                $('#link-href-field, #search-panel').show();
                $('#wp-link-wrap').addClass('search-panel-visible');
            }
            inputs.url.val($(this).val());
        });

        $( '#wp-link-search-toggle' ).click( wpLink.toggleInternalLinking );

        rivers.elements.on( 'river-select', wpLink.updateFields );

        inputs.search.keyup( function() {
            var self = this;

            window.clearTimeout( searchTimer );
            searchTimer = window.setTimeout( function() {
                wpLink.searchInternalLinks.call( self );
            }, 500 );
        });
    },

    open: function( editorId ) {
        var ed;

        wpLink.range = null;

        if ( editorId ) {
            window.wpActiveEditor = editorId;
        }

        if ( ! window.wpActiveEditor ) {
            return;
        }

        this.textarea = $( '#' + window.wpActiveEditor ).get( 0 );

        if ( typeof tinymce !== 'undefined' ) {
            ed = tinymce.get( wpActiveEditor );

            if ( ed && ! ed.isHidden() ) {
                editor = ed;
            } else {
                editor = null;
            }

            if ( editor && tinymce.isIE ) {
                editor.windowManager.bookmark = editor.selection.getBookmark();
            }
        }

        if ( ! wpLink.isMCE() && document.selection ) {
            this.textarea.focus();
            this.range = document.selection.createRange();
        }

        inputs.wrap.show();
        inputs.backdrop.show();

        wpLink.refresh();
    },

    isMCE: function() {
        return editor && ! editor.isHidden();
    },

    refresh: function() {
        // Refresh rivers (clear links, check visibility)
        rivers.search.refresh();
        rivers.recent.refresh();

        if ( wpLink.isMCE() )
            wpLink.mceRefresh();
        else
            wpLink.setDefaultValues();

        // Focus the URL field and highlight its contents.
        //     If this is moved above the selection changes,
        //     IE will show a flashing cursor over the dialog.
        inputs.url.focus()[0].select();
        // Load the most recent results if this is the first time opening the panel.
        if ( ! rivers.recent.ul.children().length )
            rivers.recent.ajax();
    },

    mceRefresh: function() {
        var e, href, newOption;

        // If link exists, select proper values.
        if ( e = editor.dom.getParent( editor.selection.getNode(), 'A' ) ) {
            // Based on href attr try to infer whether it is a shortcode or a url
            href = editor.dom.getAttrib( e, 'href' );
            newOption = inputs.urlType.find('option').filter(function(index, item) {
                return href === $(item).val();
            });

            if (newOption.length > 0) {
                inputs.urlType.val(newOption.val()).change();
            } else {
                inputs.urlType.val(inputs.urlType.find('option:first-child').val()).change();
            }

            // Set URL and description.
            inputs.url.val( editor.dom.getAttrib( e, 'href' ) );
            inputs.title.val( editor.dom.getAttrib( e, 'title' ) );
            // Set open in new tab.
            inputs.openInNewTab.prop( 'checked', ( '_blank' === editor.dom.getAttrib( e, 'target' ) ) );
            // Update save prompt.
            inputs.submit.val( wpLinkL10n.update );

            // If there's no link, set the default values.
        } else {
            wpLink.setDefaultValues();
        }
    },

    close: function() {
        if ( ! wpLink.isMCE() ) {
            wpLink.textarea.focus();

            if ( wpLink.range ) {
                wpLink.range.moveToBookmark( wpLink.range.getBookmark() );
                wpLink.range.select();
            }
        } else {
            editor.focus();
        }

        inputs.backdrop.hide();
        inputs.wrap.hide();
    },

    getAttrs: function() {
        return {
            href: inputs.url.val(),
            title: inputs.title.val(),
            target: inputs.openInNewTab.prop( 'checked' ) ? '_blank' : ''
        };
    },

    update: function() {
        if ( wpLink.isMCE() )
            wpLink.mceUpdate();
        else
            wpLink.htmlUpdate();
    },

    htmlUpdate: function() {
        var attrs, html, begin, end, cursor, title, selection,
        textarea = wpLink.textarea;

        if ( ! textarea )
            return;

        attrs = wpLink.getAttrs();

        // If there's no href, return.
        if ( ! attrs.href || attrs.href == 'http://' )
            return;

        // Build HTML
        html = '<a href="' + attrs.href + '"';

        if ( attrs.title ) {
            title = attrs.title.replace( /</g, '&lt;' ).replace( />/g, '&gt;' ).replace( /"/g, '&quot;' );
            html += ' title="' + title + '"';
        }

        if ( attrs.target ) {
            html += ' target="' + attrs.target + '"';
        }

        html += '>';

        // Insert HTML
        if ( document.selection && wpLink.range ) {
            // IE
            // Note: If no text is selected, IE will not place the cursor
            //       inside the closing tag.
            textarea.focus();
            wpLink.range.text = html + wpLink.range.text + '</a>';
            wpLink.range.moveToBookmark( wpLink.range.getBookmark() );
            wpLink.range.select();

            wpLink.range = null;
        } else if ( typeof textarea.selectionStart !== 'undefined' ) {
            // W3C
            begin       = textarea.selectionStart;
            end         = textarea.selectionEnd;
            selection   = textarea.value.substring( begin, end );
            html        = html + selection + '</a>';
            cursor      = begin + html.length;

            // If no text is selected, place the cursor inside the closing tag.
            if ( begin == end )
                cursor -= '</a>'.length;

            textarea.value = textarea.value.substring( 0, begin ) + html +
                textarea.value.substring( end, textarea.value.length );

            // Update cursor position
            textarea.selectionStart = textarea.selectionEnd = cursor;
        }

        wpLink.close();
        textarea.focus();
    },

    mceUpdate: function() {
        var link,
        attrs = wpLink.getAttrs();

        wpLink.close();
        editor.focus();

        if ( tinymce.isIE ) {
            editor.selection.moveToBookmark( editor.windowManager.bookmark );
        }

        link = editor.dom.getParent( editor.selection.getNode(), 'a[href]' );

        // If the values are empty, unlink and return
        if ( ! attrs.href || attrs.href == 'http://' ) {
            editor.execCommand( 'unlink' );
        return;
    }

               if ( link ) {
                   editor.dom.setAttribs( link, attrs );
               } else {
                   editor.execCommand( 'mceInsertLink', false, attrs );
               }

               // Move the cursor to the end of the selection
               editor.selection.collapse();
    },

    updateFields: function( e, li, originalEvent ) {
        inputs.url.val( li.children( '.item-permalink' ).val() );
        inputs.title.val( li.hasClass( 'no-title' ) ? '' : li.children( '.item-title' ).text() );
        if ( originalEvent && originalEvent.type == 'click' )
            inputs.url.focus();
    },

    setDefaultValues: function() {
        // Set URL and description to defaults.
        // Leave the new tab setting as-is.
        inputs.url.val( 'http://' );
        inputs.title.val( '' );
        inputs.urlType.val( inputs.urlType.find('option:first-child').val() ).change();

        // Update save prompt.
        inputs.submit.val( wpLinkL10n.save );
    },

    searchInternalLinks: function() {
        var t = $( this ), waiting,
        search = t.val();

        if ( search.length > 2 ) {
            rivers.recent.hide();
            rivers.search.show();

            // Don't search if the keypress didn't change the title.
            if ( wpLink.lastSearch == search )
                return;

            wpLink.lastSearch = search;
            waiting = t.parent().find('.spinner').show();

            rivers.search.change( search );
            rivers.search.ajax( function() {
                waiting.hide();
            });
        } else {
            rivers.search.hide();
            rivers.recent.show();
        }
    },

    next: function() {
        rivers.search.next();
        rivers.recent.next();
    },

    prev: function() {
        rivers.search.prev();
        rivers.recent.prev();
    },

    keydown: function( event ) {
        var fn, id,
        key = $.ui.keyCode;

        if ( key.ESCAPE === event.keyCode ) {
            wpLink.close();
            event.stopImmediatePropagation();
        } else if ( key.TAB === event.keyCode ) {
            id = event.target.id;

            if ( id === 'wp-link-submit' && ! event.shiftKey ) {
                inputs.close.focus();
                event.preventDefault();
            } else if ( id === 'wp-link-close' && event.shiftKey ) {
                inputs.submit.focus();
                event.preventDefault();
            }
        }

        if ( event.keyCode !== key.UP && event.keyCode !== key.DOWN ) {
            return;
        }

        fn = event.keyCode === key.UP ? 'prev' : 'next';
        clearInterval( wpLink.keyInterval );
        wpLink[ fn ]();
        wpLink.keyInterval = setInterval( wpLink[ fn ], wpLink.keySensitivity );
        event.preventDefault();
    },

    keyup: function( event ) {
        var key = $.ui.keyCode;

        if ( event.which === key.UP || event.which === key.DOWN ) {
            clearInterval( wpLink.keyInterval );
            event.preventDefault();
        }
    },

    delayedCallback: function( func, delay ) {
        var timeoutTriggered, funcTriggered, funcArgs, funcContext;

        if ( ! delay )
            return func;

        setTimeout( function() {
            if ( funcTriggered )
            return func.apply( funcContext, funcArgs );
        // Otherwise, wait.
        timeoutTriggered = true;
        }, delay );

        return function() {
            if ( timeoutTriggered )
                return func.apply( this, arguments );
            // Otherwise, wait.
            funcArgs = arguments;
            funcContext = this;
            funcTriggered = true;
        };
    },

    toggleInternalLinking: function() {
        var visible = inputs.wrap.hasClass( 'search-panel-visible' );

        inputs.wrap.toggleClass( 'search-panel-visible', ! visible );
        setUserSetting( 'wplink', visible ? '0' : '1' );
        inputs[ ! visible ? 'search' : 'url' ].focus();
    }
    };

    River = function( element, search ) {
        var self = this;
        this.element = element;
        this.ul = element.children( 'ul' );
        this.contentHeight = element.children( '#link-selector-height' );
        this.waiting = element.find('.river-waiting');

        this.change( search );
        this.refresh();

        $( '#wp-link .query-results, #wp-link #link-selector' ).scroll( function() {
            self.maybeLoad();
        });
        element.on( 'click', 'li', function( event ) {
            self.select( $( this ), event );
        });
    };

    $.extend( River.prototype, {
        refresh: function() {
            this.deselect();
            this.visible = this.element.is( ':visible' );
        },
        show: function() {
            if ( ! this.visible ) {
                this.deselect();
                this.element.show();
                this.visible = true;
            }
        },
        hide: function() {
            this.element.hide();
            this.visible = false;
        },
        // Selects a list item and triggers the river-select event.
        select: function( li, event ) {
            var liHeight, elHeight, liTop, elTop;

            if ( li.hasClass( 'unselectable' ) || li == this.selected )
                return;

            this.deselect();
            this.selected = li.addClass( 'selected' );
            // Make sure the element is visible
            liHeight = li.outerHeight();
            elHeight = this.element.height();
            liTop = li.position().top;
            elTop = this.element.scrollTop();

            if ( liTop < 0 ) // Make first visible element
                this.element.scrollTop( elTop + liTop );
            else if ( liTop + liHeight > elHeight ) // Make last visible element
                this.element.scrollTop( elTop + liTop - elHeight + liHeight );

            // Trigger the river-select event
            this.element.trigger( 'river-select', [ li, event, this ] );
        },
        deselect: function() {
            if ( this.selected )
                this.selected.removeClass( 'selected' );
            this.selected = false;
        },
        prev: function() {
            if ( ! this.visible )
                return;

            var to;
            if ( this.selected ) {
                to = this.selected.prev( 'li' );
                if ( to.length )
                    this.select( to );
            }
        },
        next: function() {
            if ( ! this.visible )
                return;

            var to = this.selected ? this.selected.next( 'li' ) : $( 'li:not(.unselectable):first', this.element );
            if ( to.length )
                this.select( to );
        },
        ajax: function( callback ) {
            var self = this,
            delay = this.query.page == 1 ? 0 : wpLink.minRiverAJAXDuration,
            response = wpLink.delayedCallback( function( results, params ) {
                self.process( results, params );
                if ( callback )
                callback( results, params );
            }, delay );

            this.query.ajax( response );
        },
        change: function( search ) {
            if ( this.query && this._search == search )
                return;

            this._search = search;
            this.query = new Query( search );
            this.element.scrollTop( 0 );
        },
        process: function( results, params ) {
            var list = '', alt = true, classes = '',
            firstPage = params.page == 1;

            if ( ! results ) {
                if ( firstPage ) {
                    list += '<li class="unselectable"><span class="item-title"><em>' +
                        wpLinkL10n.noMatchesFound + '</em></span></li>';
                }
            } else {
                $.each( results, function() {
                    classes = alt ? 'alternate' : '';
                    classes += this.title ? '' : ' no-title';
                    list += classes ? '<li class="' + classes + '">' : '<li>';
                    list += '<input type="hidden" class="item-permalink" value="' + this.permalink + '" />';
                    list += '<span class="item-title">';
                    list += this.title ? this.title : wpLinkL10n.noTitle;
                    list += '</span><span class="item-info">' + this.info + '</span></li>';
                    alt = ! alt;
                });
            }

            this.ul[ firstPage ? 'html' : 'append' ]( list );
        },
        maybeLoad: function() {
            var self = this,
            el = this.element,
            bottom = el.scrollTop() + el.height();

            if ( ! this.query.ready() || bottom < this.contentHeight.height() - wpLink.riverBottomThreshold )
                return;

            setTimeout(function() {
                var newTop = el.scrollTop(),
                newBottom = newTop + el.height();

            if ( ! self.query.ready() || newBottom < self.contentHeight.height() - wpLink.riverBottomThreshold )
                return;

            self.waiting.show();
            el.scrollTop( newTop + self.waiting.outerHeight() );

            self.ajax( function() {
                self.waiting.hide();
            });
            }, wpLink.timeToTriggerRiver );
        }
    });

    Query = function( search ) {
        this.page = 1;
        this.allLoaded = false;
        this.querying = false;
        this.search = search;
    };

    $.extend( Query.prototype, {
        ready: function() {
            return ! ( this.querying || this.allLoaded );
        },
        ajax: function( callback ) {
            var self = this,
        query = {
            action : 'wp-link-ajax',
        page : this.page,
        '_ajax_linking_nonce' : inputs.nonce.val()
        };

    if ( this.search )
        query.search = this.search;

    this.querying = true;

    $.post( ajaxurl, query, function( r ) {
        self.page++;
        self.querying = false;
        self.allLoaded = ! r;
        callback( r, query );
    }, 'json' );
        }
    });

    $( document ).ready( wpLink.init );
})( jQuery );
